Study on Partial Replacement of Cement with Animal Bone Ash in Concrete at Elevated Temperatures

Abstract

AbstractIt is not uncommon to find inefficient waste disposal systems in third world countries like in Ethiopia where the human factor is crucial in generating wastes like animal bones. Animal bone ash constitutes high calcium, offering good binding characteristics to employ bone ash (BA) as a partial replacement of cement in concrete production. This study experimentally investigates use of animal bone ash (BA) as partial replacement of cement in structural concrete production at elevated temperature. Parameters studied in this study include elevated temperature intensity (300 °C, 600 °C and 900 °C), duration of temperature exposure (1 h and 3 h), cooling methods and various bone ash (BA) cement blending percentages (0%, 5%, 10%, 15% and 20%). A total of 237 concrete cylindrical test specimens was casted and tested to study behavior of concrete with cement replaced by bone ash (BA) at elevated temperatures. Experimental test results showed that weight, tensile and compressive strengths of bone ash blended cement concrete reduced with an increase in temperature and their respective test values depends on choice of cooling methods. Fast cooling exhibited an additional strength loss of 35% as compared to natural air cooling. Also, concrete residual compressive strength decreases sharply beyond 10% replacement of cement with bone ash (BA). This implies optimum threshold value of bone ash (BA) replacement of cement in concrete at elevated temperature is 10%.KeywordsElevated temperatureCement partial replacementAnimal Bone ash (BA)